Reagent-grade metal.
An example of the element Bismuth

Reagent-grade metal.
Around 2001 Stephen Wolfram asked Ed Pegg and me if we could experiment with growing hopper crystals with bismuth. Ed bought some from Alfa Aesar and I brought in my small electric kiln to the office. We were able to create crystals almost immediately: Simply pouring into a stainless steel measuring cup, allowing to cool until the outer edge is solid, then pouring the center off is all it takes. We made several nice small hopper crystals, and it's obvious that one could make any number just by refining the conditions and using more bismuth.
See the fourth sample for a picture of one dish of crystals I made, along with a video showing how the liquid metal is poured off from the crystals.Source:Alfa AesarContributor:Ed Pegg JrAcquired:15 April, 2002Price: $100/KgSize: 2"Purity: 99.9%